The present invention relates to a quality design processing tool and techniques enabled by such tool and, more particularly, the present invention relates to a computerized tool and techniques that allow for integrating a quality function deployment (QFD) tool with a critical to quality (CTQ) tool.
A system can be represented as an assemblage of elements working in tandem and forming a unitary object that performs one or more tasks. Typically, components of a system cannot meet the objectives assigned to the whole system. Therefore, a system may be described by its elements, their merits, and the relationships that tie them together. In addition, a component of a system can itself be a system. For example, an engine is a component of another system, an airplane, which in turn can be a part of a bigger system, air transportation, and so on. A tree structure of system, sub-systems, components, parts, etc. can be utilized to represent a system. FIG. 1 shows one typical prior art architecture representation of an exemplary projector system which includes sub-system and component levels.
The ability of the system to meet its assigned objective can be gauged using certain figures of merit or critical to quality (CTQ) parameters. Similarly, each element of the system has its own list of CTQ""s upon which the performance of the element as part of the system can be gauged. The values of the CTQ""s at a first level (e.g., the system level) may depend on the values of the CTQ""s at subsequent levels (e.g. sub-system and component levels).
Techniques have been developed to define CTQ""s at various system levels so that the overall system CTQ""s can be met. Generally, a quality function deployment (QFD) tool allows for identifying CTQ""s and flowing them down to subsequent levels. FIG. 2 is a block diagram of a known CTQ flow down process. The relationship between each level CTQ""s and key control parameters (KCP""s) has been referred to as a house of quality. FIG. 2 shows the flow of CTQ""s from the customer requirements to functional requirements and then to part characteristics down to manufacturing processes CTQ""s and to process variables. At each level, the CTQ""s are identified and their relations to the higher level CTQ""s are specified qualitatively by respective entries, such as high (designated h), medium (designated m), or low (designated l), depending on the relation strength. FIG. 3 is typical prior art house of quality or quality matrix relating customer expectations represented by CTQ""s 2 to product requirements represented by key control parameters 4 (KCP""s). FIG. 3 illustrates the qualitative effect that each KCP 4 has on one or more CTQ""s 2.
When applied at the system level of the example in FIG. 1, QFD will yield a first house of quality for that system as shown in FIG. 3. In that house of quality, KCP""s 4 corresponding to different sub-systems of the overall system (e.g. lamp, cooling, lens) are not arranged in any order. This generally results in a loss of the system architecture and renders analysis of sub-system and component requirements difficult. The problem is particularly evident when flowing down the CTQ""s to components and parts of each subsystem. If the tree structure in FIG. 1 is deep or complex, the CTQ list will rapidly grow in size and the system structure will be difficult, if not impossible, to ascertain. Therefore, known QFD tools may be somewhat valuable for xe2x80x9cshallowxe2x80x9d systems (e.g., systems with a limited number of elements and levels) but have disadvantages when applied to xe2x80x9cdeepxe2x80x9d systems having numerous levels and components. Moreover, prior to the present invention, there have been no direct links between the QFD tool and the CTQ tool. Thus, the extent to which the top customer needs are met may not be directly tracked. Further, there is no automated requirements"" management tracking, and system design trade-off tool.
In view of the foregoing, it would be desirable to provide an improved quality design tool with direct links between the QFD tool and the CTQ tool, so that the extent to which the top customer needs are met may be quickly and reliably tracked down to the subsystem level. It would be further desirable to provide a tool capable of executing automated requirements"" management tracking, and system design trade-off that would permit continuous evaluation of design alternatives. Additionally, it would be desirable to provide an improved quality tool that enables the evaluation of system and subsystem design capability to help identify potential new customers/markets and technologies.
It will be appreciated that many systems designed to meet specific top customer needs often satisfy a subset of requirements for a different product/customer. Also, systems meeting customer needs for a particular product often satisfy some additional ones (xe2x80x9cBonus Capabilityxe2x80x9d). Such systems may require relatively minor modifications/additions to satisfy additional derivative market needs unrelated to the original. Thus, it would be desirable to provide an improved quality design tool that would allow for bypassing years of costly and lengthy development efforts when derivative products are designed from a base system to serve new markets.
Generally speaking, one aspect of the present invention fulfills the foregoing needs by providing in one exemplary embodiment a method for integrating a quality function deployment tool with a critical to quality tool. Each of the tools comprises a computer-enabled tool. The method allows for executing quality function deployment at each of a plurality of levels with the quality function deployment tool for a system designable from a respective family of subsystem alternatives. The method further allows for generating quality matrices indicating a relationship between an original set of critical to quality characteristics and key control parameters with the critical to quality tool for the respective family of subsystem alternatives. A linking action allows for linking the quality function deployment tool to the critical to quality tool for tracking at each level the extent to which the original set of critical to quality characteristics is met by each respective family of subsystem alternatives.
The present invention may further fulfill the foregoing needs by providing in another aspect thereof a computer-readable medium encoded with computer program code for integrating a quality function deployment tool with a critical to quality tool. The program code causing a computer to execute a method comprising:
executing quality function deployment at each of a plurality of levels with the quality function deployment tool for a system designable from a respective family of subsystem alternatives for an original system design;
generating quality matrices indicating a relationship between an original set of critical to quality characteristics and key control parameters with the critical to quality tool for the respective family of subsystem alternatives, the original set of critical to quality parameters based on predefined data for the original system design;
linking the quality function deployment tool to the critical to quality tool for tracking at each level the extent to which the original set of critical to quality characteristics is met by each respective family of subsystem alternatives;
tracking at each level the extent to which each respective family of subsystem alternatives meets a modified set of critical to quality parameters based on new data for the original system design; and
determining for each family of subsystem alternatives a derivative of one or more subsystem alternatives that meets the modified set of critical to quality parameters.
The present invention may still further fulfill the foregoing needs by providing in yet another aspect thereof a processor configured to integrate a quality function deployment tool with a critical to quality tool. The processor may comprise a processor module configured to execute quality function deployment at each of a plurality of levels for a system designable from a respective family of subsystem alternatives for an original system design. A generator module is configured to generate quality matrices indicating a relationship between an original set of critical to quality characteristics and key control parameters for the respective family of subsystem alternatives. The original set of critical to quality parameters may be based on predefined data for the original system design. A linking module is configured to link the quality function deployment tool to the critical to quality tool to track at each level the extent to which the original set of critical to quality characteristics is met by each respective family of subsystem alternatives. A tracking module is configured to track at each level the extent to which each respective family of subsystem alternatives meets a modified set of critical to quality parameters based on new data for the original system design. A processing module is configured to determine for each family of subsystem alternatives a derivative of one or more subsystem alternatives that meets the modified set of critical to quality parameters. A coupling module is configured to selectably couple respective modules representative of respective members of each family of subsystem alternatives to determine effects to the set of critical to quality parameters caused by the selectably coupled modules.